.m {
  margin: 20px;
}
.mt {
  margin-top: 20px;
}
.mr {
  margin-right: 20px;
}
.mb {
  margin-bottom: 20px;
}
.ml {
  margin-left: 20px;
}

.mlr {
  margin-left: 20px;
  margin-right: 20px;
}
